This invention relates to gas turbine engines and, more particularly, to a gas turbine engine having a variable fan nozzle integrated with a thrust reverser of the gas turbine engine.
Gas turbine engines are widely known and used for power generation and vehicle (e.g., aircraft) propulsion. A typical gas turbine engine includes a compression section, a combustion section, and a turbine section that utilize a primary airflow into the engine to generate power or propel the vehicle. The gas turbine engine is typically mounted within a housing, such as a nacelle. A bypass airflow flows through a passage between the housing and the engine and exits from the engine at an outlet.
Presently, conventional thrust reversers are used to generate a reverse thrust force to slow forward movement of a vehicle, such as an aircraft. One type of conventional thrust reverser utilizes a moveable door stowed near the rear of the nacelle. After touch-down of the aircraft for landing, the door moves into the bypass airflow passage to deflect the bypass airflow radially outwards into cascades, or vents, that direct the discharge airflow in a forward direction to slow the aircraft. Although effective, this and other conventional thrust reversers serve only for thrust reversal and, when in the stowed position for non-landing conditions, do not provide additional functionality. The use of a variable area fan nozzle (VAFN) has been proposed for low pressure ratio fan designs to improve the propulsive efficiency of high bypass ratio gas turbine engines. Integrating the VAFN functionality into a common set of thrust reverser cascades operated by a common actuation system represents a significant reduction in complexity and weight.